Add DelayNetwork

Author: Hespe

lib/networks/DelayNetwork.m

@@ -0,0 +1,86 @@
+%---------------------------------------------------------------------------------------------------
+% Copyright (c) Institute of Control Systems, Hamburg University of Technology. All rights reserved.
+% Licensed under the GPLv3. See LICENSE in the project root for license information.
+% Author(s): Christian Hespe
+%---------------------------------------------------------------------------------------------------
+
+classdef DelayNetwork < MatlabNetwork
+    %DELAYNETWORK Network implementation that simulates a constant and uniform delay during
+    %transmission
+    %   This implementation of BaseNetwork does not consider any stochastic
+    %   effects during transmission, but is subject to a constant and
+    %   uniform delay for all informaton transmitted through the net
+    
+    properties(GetAccess = public, SetAccess = immutable)
+        range % Range of the communication
+        delay % Transmission delay
+    end
+
+    properties(GetAccess = private, SetAccess = private)
+        buffer % Delay buffer
+        idx    % buffer index
+    end
+
+    methods
+        function obj = DelayNetwork(agentCount, cycleTime, dim, range, delay)
+            %DELAYNETWORK Construct an instance of this class
+            %   The network needs several parameter to be correctly
+            %   initialized.
+            %
+            %   agentCount    Number of agents in the network
+            %   dim           Dimension of the underlying space
+            %   range         Communication range
+            %   delay         Communication delay in steps
+            
+            % Initialize MatlabNetwork properties
+            obj@MatlabNetwork(agentCount, cycleTime, dim);
+            
+            obj.range = range;
+            obj.delay = delay;
+
+            obj.idx    = 1;
+            obj.buffer = cell(agentCount, delay+1);
+        end
+                
+        function recvMessages = process(obj) 
+            %PROCESS Processes all messages that were send by the agents
+            %since the last call.
+            %   The messages get broadcasted to all agents in the receiving
+            %   range.
+            
+            sentMessages = obj.sentMessages.takeAll();
+            
+            % Initialize every message as received by everyone
+            filter = ones([length(sentMessages), obj.agentCount], 'logical');
+            
+            % Compute the recipients of each message
+            for i = 1:length(sentMessages)
+                pos_sender = obj.positions(:, sentMessages(i).sender);
+                
+                % Exclude the possibility of agents sending to themselves
+                filter(i, sentMessages(i).sender) = false;
+                
+                % Calculate the distance from the sender to all agents
+                dist = vecnorm(pos_sender - obj.positions);
+                
+                % Remove receivers that are outside the transmission range
+                filter(i,:) = filter(i,:) & (dist <= obj.range);
+            end
+            
+            % Copy all received messages in the delay buffers
+            for i = 1:obj.agentCount
+                obj.buffer{i,obj.idx} = sentMessages(filter(:,i));
+            end
+
+            % Prepare receive buffer and advance the index
+            recvMessages = obj.buffer(:, obj.mask(obj.idx-1));
+            obj.idx      = obj.mask(obj.idx+1);
+        end
+    end
+
+    methods(Access = private)
+        function idx = mask(obj, idx)
+            idx = mod(idx-1, obj.delay+1) + 1;
+        end
+    end
+end